This invention relates to monitoring liquid level in tanks, and more particularly to a system and method for indicating a liquid level condition within a tank.
The determination of liquid level within LPG or fuel oil tanks is typically performed by a mechanical float-type gauge that extends into the tank. One type of gauge is disclosed in U.S. Pat. No. 6,041,650 to Swindler, et al., and includes a movable float arm coupled by gears to the lower end of a rotatable shaft. A magnet is mounted to the upper end of the shaft and extends into a passage of a gauge head for magnetic coupling with a level indicating dial. A change in liquid level within the tank causes movement of the float arm and thus rotation of the indicating dial to thereby show the amount of liquid within the tank.
Although the above-described system is adequate for indicating liquid level, it is often inconvenient for will-call status customers, i.e. those that must call a fuel supply company for tank refill, to read the gauge head. For stationary tanks, a person must exit the building, approach the tank and move a cover that extends over the gauge head and other fittings in order to ascertain whether or not a fuel supply company should be contacted for refilling the tank. Consequently, many stationary tanks run out of fuel at the most inconvenient times, such as during heating, cooking, bathing, and so on. However, such inconveniences pale in comparison to potentially more serious consequences, such as frozen pipes during winter conditions and the attendant damage and repair costs, health degradation among the young, elderly, sick and invalid when exposed to low temperature conditions, and so on. The difficulty in ascertaining fuel level within the tank is exacerbated during harsh winter months where the desire or effort to read the gauge is dampened, especially when ice or snow is present, or simply at any time when one feels that weather conditions are unfavorable for such a task.
Accordingly, there is a need to facilitate the determination of a low liquid level condition within a fuel tank or the like from a remote location, such as from a window inside a home or other convenient viewing location, in time for an observer to alert a fuel provider of the need to refill the tank.